The historic nature of the find was brought to the department's attention by a passerby. Julie Snell, a self-described tree geek who teaches a Temple University class on urban ecosystems, saw the scene while biking and contacted Water Department historian Adam Levine, whom Snell had previously heard speak about wooden water mains.

Snell's intervention led to the wooden mains' being saved for use in educational demonstrations, the department said.

Jon Snyder / Staff

Water Department crews found 200-year-old wooden mains while replacing a line in Center City.

The wooden pipes were apparently laid on "Back of Spruce, from Ninth to Tenth" between October 1811 and October 1812, according to a report from the department's archives. The department said Levine's research showed that the wooden pipe there was replaced in 1831 by a 12-inch cast-iron main.

Philadelphia began installing cast-iron pipes in 1819 and took its last wooden pipes out of service in 1858, though the pipes were not necessarily removed as they stopped being put to use.

Jon snyder / Staff

The wooden mains were taken out of use long ago, but not removed from the ground under the 900 block of Spruce Street until this week.